The present disclosure generally relates to diodes, and more specifically, to vertical diodes in Fin-type integrated circuit structures.
Fin-type field effect transistors (FinFETs) utilize a fin-shaped semiconductor body as the main transistor element. The center (channel) of the fin is a semiconductor and the ends of the fin are conductors, while an overlying gate supplies a voltage field to alter the conductivity of the fin center.
Diodes comprise a p-n junction that allows current to flow in a specified direction between an anode and a cathode. There are many types of diodes; however, diodes in general require an initial threshold to be exceeded before current can pass. Some diodes can be controlled with one or more gates to determine how easily the current can pass through the diode.
However, diodes are not readily amenable to fin structures because, rather than transistors that have a single channel with conductive source and drain structures that can be readily doped with impurities once the overlying gate or gate oxide is formed over the fin structure, diodes utilize multiple closely spaced impurities that are not easily aligned (especially in dual gate field effect diodes). Therefore, diodes are not readily formed using fin-type transistor structures.